Information given by websites selling home self-sampling COVID-19 tests: an analysis of accuracy and completeness

Sian Taylor-Phillips; Sarah Berhane; Alice J Sitch; Karoline Freeman; Malcolm James Price; Clare Davenport; Julia Geppert; Isobel M Harris; Osemeke Osokogu; Magdalena Skrybant; Jonathan J Deeks

doi:10.1136/bmjopen-2020-042453

Information given by websites selling home self-sampling COVID-19 tests: an analysis of accuracy and completeness

BMJ Open. 2020 Nov 6;10(11):e042453. doi: 10.1136/bmjopen-2020-042453.

Authors

Sian Taylor-Phillips^{1

2}, Sarah Berhane^{2

3}, Alice J Sitch^{2

3}, Karoline Freeman^{4

2}, Malcolm James Price^{2

3}, Clare Davenport^{2

3}, Julia Geppert⁴, Isobel M Harris², Osemeke Osokogu⁴, Magdalena Skrybant^{2

5}, Jonathan J Deeks^{2

3}

Affiliations

¹ Warwick Medical School, University of Warwick, Coventry, UK s.taylor-phillips@warwick.ac.uk.
² Institute of Applied Health Research, University of Birmingham, Birmingham, UK.
³ NIHR Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, UK.
⁴ Warwick Medical School, University of Warwick, Coventry, UK.
⁵ NIHR Applied Research Collaboration West Midlands, University of Warwick, Coventry, UK.

Abstract

Objectives: To assess the accuracy and completeness of information provided by websites selling home self-sampling and testing kits for COVID-19.

Design: Cross-sectional observational study.

Setting: All websites (n=27) selling direct to user home self-sampling and testing kits for COVID-19 (41 tests) in the UK (39 tests) and USA (two tests) identified by a website search on 23 May 2020.

Main outcome measures: Thirteen predefined basic information items to communicate to a user, including who should be tested, when and how testing should be done, test accuracy, and interpretation of results.

Results: Many websites did not provide the name or manufacturer of the test (32/41; 78%), when to use the test (10/41; 24%), test accuracy (12/41; 29%), and how to interpret results (21/41; 51%). Sensitivity and specificity were the most commonly reported test accuracy measures (either reported for 27/41 [66%] tests): we could only link these figures to manufacturers' documents or publications for four (10%) tests. Predictive values, most relevant to users, were rarely reported (five [12%] tests reported positive predictive values). For molecular virus tests, 9/23 (39%) websites explained that test positives should self-isolate, and 8/23 (35%) explained that test negatives may still have the disease. For antibody tests, 12/18 (67%) websites explained that testing positive does not necessarily infer immunity from future infection. Seven (39%) websites selling antibody tests claimed the test had a CE mark, when they were for a different intended use (venous blood rather than finger-prick samples).

Conclusions: At the point of online purchase of home self-sampling COVID-19 tests, users in the UK are provided with incomplete, and, in some cases, misleading information on test accuracy, intended use, and test interpretation. Best practice guidance for communication about tests to the public should be developed and enforced for online sales of COVID-19 tests.

Keywords: COVID-19; health policy; infectious diseases; public health.

Publication types

Observational Study
Research Support, Non-U.S. Gov't

MeSH terms

COVID-19 / diagnosis*
COVID-19 / epidemiology
COVID-19 Testing / methods*
Cross-Sectional Studies
Humans
Internet*
Pandemics*
Reproducibility of Results
SARS-CoV-2*
Specimen Handling / methods*

Abstract

Publication types

MeSH terms

Grants and funding